Evaluation of six cucumber greenhouse cultivars for resistance to Tetranychus turkestani (Acari: Tetranychidae)

The strawberry spider mite (SSM), Tetranychus turkestani Ugarov & Nikolski, is an important pest of greenhouse cucumber in tropical and temperate regions of the world. The use of the host plant resistance is a basic method to reduce pesticide application in greenhouses. In this study, the biological responses of SSM to six greenhouse cucumber cultivars (Puia, Hedieh, Milad Ghadim, Milad Jadid, Khasib and Negin) were investigated. Non-choice tests were performed to evaluate the interaction between the host plant-mite. All tests of this study were carried out under laboratory conditions at 28 ± 1 °C, 60 ± 5% RH and 16:8 h (L: D) in a walk-in growth chamber. The results indicated that immature development time and adult longevity of SSM was significantly influenced by cucumber cultivars. The highest r, λ, and R₀ were 0.275 (day^-1), 1.316 (day^-1) and 36.180 (offspring/generation) all of which were recorded for the mites reared on the Hedieh cultivar. No significant difference was observed for these parameters among the other cultivars. Mean generation times of T. turkestani reared on Negin (14.020 day) and Milad Ghadim (13.57 day) cultivars were significantly longer than for the other cultivars. This mite had the shortest generation time on Puia cultivar (11.43 day). In conclusion, it seems that Hedieh and Milad Jadid cultivars are the more susceptible and resistant cultivars to the SSM than the other tested cultivars, respectively.